Validation of multiparametric tetramer staining Principle of the validation

While the detection of serological response is well described and objects of numerous guidance, much less information is available on validation of methodology for the detection of cellular immunologic response responses. A recently developed approach uses tetrameric complexes of HLA molecules to stain antigen-specific T cells in FACS analysis. Tetramer staining presents advantages over traditional ELISPOT assays as it does not require a cell stimulation period likely to exert a selective pressure on Tcell subpopulations. However, interpretation of tetramer staining in the setting of cancer immunotherapeutic products presents a challenge because of the low number of cells involved in individual epitope response that can be detected in the peripheral circulation.